upd70f3422gj-gae-qs-ax Renesas Electronics Corporation., upd70f3422gj-gae-qs-ax Datasheet - Page 656

• Manufacturer Part Number: upd70f3422gj-gae-qs-ax
• Description: 32-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

Chapter 19
656
Table 19-12
(2)
(3)
(4)
Output timing of error frame
Output timing of error frame
Processing in case of error
The transmission node re-transmits the data frame or remote frame after the
error frame. (However, it does not re-transmit the frame in the single-shot
mode.)
Error state
(a) Types of error states
The following three types of error states are defined by the CAN specification:
• Error active
• Error passive
• Bus-off
These types of error states are classified by the values of the CnERC.TEC7 to
CnERC.TEC0 bits (transmission error counter bits) and the CnERC.REC6 to
CnERC.REC0 bits (reception error counter bits) as shown in Table 19-13.
The present error state is indicated by the CnINFO register.
When each error counter value becomes equal to or greater than the error
warning level (96), the CnINFO.TECS0 or CnINFO.RECS0 bit is set to 1. In
this case, the bus state must be tested because it is considered that the bus
has a serious fault. An error counter value of 128 or more indicates an error
passive state and the TECS1 or RECS1 bit is set to 1.
• If the value of the transmission error counter is greater than or equal to 256
• If only one node is active on the bus at startup (i.e., when the bus is
Preliminary User’s Manual U17566EE1V2UM00
Type
Bit error, stuff error,
form error, ACK error
CEC error
(actually, the transmission error counter does not indicate a value greater
than or equal to 256), the bus-off state is reached and the CnINFO.BOFF bit
is set to 1.
connected only to the local station), ACK is not returned even if data is
transmitted. Consequently, re-transmission of the error frame and data is
repeated. In the error passive state, however, the transmission error counter
is not incremented and the bus-off state is not reached.
Output Timing
Error frame output is started at the timing of the bit following
the detected error.
Error frame output is started at the timing of the bit following
the ACK delimiter.
CAN Controller (CAN)